It is common knowledge that industrial production lines in factories operate together in order to produce semi-finished products (unfinished products) for assembly into finished products (final products). Control over the output of semi-finished products by managers at a particular stage of the production line and production schedules cannot be timely, complete and accurate due to the delay in the reporting system of statistics on the output (report cards from each stage of production). This means that the output in semi-finished products at one particular manufacturing stage may be in excess, while the production of semi-finished products at another stage may be insufficient and they cannot be assembled in a synchronized fashion as finished products. This may result in a lower finished product output, higher semi-finished products outputs, and a backlog of unfinished products on the production lines. This can cause damage to a manufacturer, including for example penalties for late delivery, over production of schedules, financial costs for a backlog of unfinished products, lower turnovers and similar problems. A further problem is that workers cannot know at the time they are working exactly what their rate of productivity is, or the amount they have earned in respect of each day, week or month that they have worked. These problems have a negative effect on the productivity of workers generally.
As illustrated in FIG. 27, what the production lines of factories using an intensive labor force, such as textiles, wood, leather, fisheries, and assembly lines generally substantially have in common is that the fabrication process of the products are all carried out in a pre-defined way and are divided into several different stages of production in a sequential order and the last stage of the assembly sequence is to create the finished product. Each employee has responsibilities relating to the operation of one or more stages in the production process. Each individual production line will usually have between 20 and 100 workers, depending on the production scale of the factory. Each production line will have an intermediate manager, who is the line manager, and is responsible for management and who allocates a sequential stage of production to each worker in the line.
To track the progress of production in a line there may often be a unit responsible for compiling statistics on the productivity of each employee during a certain period of time according to the workers' own record (such as a sequential report card) or by the particular worker's predefined record. The contents usually include: the employee's name, the product name (also known as the product code), the serial number of the stage in the production manufacturing process (also known as code of sequence), the number of stages that have been completed, the production time spent, and so on . . . . A sample of a sequential report card is illustrated in FIG. 28.
The compilation of report cards by workers in the line will provide the line manager with the progress of the production line at the time that the statistics are received.
The report card provides a basis for determining:
The productivity of each worker and of the line of production;
The wages relating to productivity/performance (which are adopted in industrial factories);
Determine the progress of production at the time the statistics are received;
Decisions by senior management to adjust production (implementing more shifts, overtime production, and rationalization of the responsibilities of the workers . . . ) maintaining deliveries on time.
But this management system of a production line has the following limitations:                Sequential records are made up manually by the workers, and are time consuming, often incorrect and involve a certain delay (they are usually compiled at the end of a shift or a working day).        It is necessary to deploy a unit to be responsible for monitoring, checking and comparing the sequential report cards.        Line managers do not always have the time necessary to collect and compile the report cards on a daily basis. This means that the results of productivity and the progress of production in the production line may be vague and inexact.        The statistical report on the progress, productivity and wages of workers in factories cannot be updated in a timely way so as to provide an instant summary of production in the factory.        The workers often will often not know their exact wage entitlement after they have completed each working day.        The process of wage calculation is frequently incorrect because workers often make inaccurate records. This in turn leads to wage disputes with workers.        Too much depends on the discretion of line managers and foremen in production management when decisions are based on incomplete or delayed production data.        An inability to make timely decisions to adjust production may cause a backlog of semi-finished products.        An accounting department may sometimes find it difficult to calculate wages for unit production based on report cards submitted by workers.        
If production planning is inaccurate, and cannot be adjusted in a timely fashion, this may also lead to delays in delivery schedules.